Too Much Treadmill Can Make You Fatter -- The Gym Spy

Flickr Photo by SashaWTaylor Ryan, The Stir's personal trainer, is sleuthing the gyms and clubs, reporting on common workout mistakes that hold us back from the killer body we want.

The gym intell:

Yesterday morning I was concentrating on my barbell dead-lift when I noticed a women I'll call "Tammy" on the treadmill. Tammy was jogging slowly from the beginning to end of my 40-minute workout.

Then I hopped on the elliptical for a quick interval set, and Tammy was still jogging her tush off (or so she thought). Finally she stepped off, wiped the sweat off her forehead, and walked over to the weights: She did two sets of bicep curls, three sets of leg curls, and she was out the door.

Sound like you? Here's why too much time on the treadmill will actually work against you and what you should do to fix it.

The error:

People devote way too much time to cardiovascular workouts and not enough time to the program that really gives results: weights. When it comes to heart and lung health, cardio is top dog. But for fat burning, muscle toning, and metabolism boosting, weight training is superb.

In fact, cardio can actually cause you to gain body fat.

Take Tammy. She's "skinny" fat: thin framed but still covered with layer of body fat. While cardio may help the scale go down initially, it does the same to your metabolism.

When you run at the same pace for a long time, your body needs energy to keep going. So it turns to the best source ... not only your saddlebags but your lean sexy muscle. And since it takes calories and energy to keep muscle, the more you lose the slower your metabolism. Now, if you used to burn 1,800 calories a day doing nothing, you may only burn 1,600 calories.

Weight training creates more lean muscle and increases your metabolism, helping you stay toned, but also burning more body fat.

New workout mission:

Women like Tammy need total body workouts. The bigger the moves, the more calories you blast. Those little bicep curls did a whole lot of nothing for Tammy's arms. Here's the program I would set for her:

Three sets of 12 reps of exercises where you work your upper and lower body at the same time: squat-to-press, walking lunges with bicep curl, or my favorite, push-up rows. And, yes, it is possible to lift weights and not "bulk" up, if that's what you want. Just lift lighter weights and increase the repetitions. This should take about 30 minutes.

Finish off with a few sprint intervals on the treadmill, bike or elliptical. Intervals are high intensity -- in other words, a mix of running at various speeds from slow to sprint -- and this doesn't need to last longer than 20 minutes in total.

For most people a sprint is a speed that can't be kept up for over one minute. If you're on a treadmill, this may be anywhere from a speed of 6-12 depending on your fitness. Try to do a total of 6-60 second sprints with a speedy walking recovery for two minutes in between.